CVE-2020-8911

A padding oracle vulnerability exists in the AWS S3 Crypto SDK for GoLang versions prior to V2. The SDK allows users to encrypt files with AES-CBC without computing a Message Authentication Code (MAC), which then allows an attacker who has write access to the target's S3 bucket and can observe whether or not an endpoint with access to the key can decrypt a file, they can reconstruct the plaintext with (on average) 128*length (plaintext) queries to the endpoint, by exploiting CBC's ability to manipulate the bytes of the next block and PKCS5 padding errors. It is recommended to update your SDK to V2 or later, and re-encrypt your files.

CVSS v3 5.6 MEDIUM
CVSS v2.0 2.1 LOW

5.6^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.1 / Impact : 4.0

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope CHANGED

2.1^/10

CVSS v2.0 : LOW

Vector : AV:L/AC:L/Au:N/C:P/I:N/A:N

Exploitability : 3.9 / Impact : 2.9

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact NONE

Availability Impact NONE

References

Link	Resource
https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09	Vendor Advisory
https://github.com/google/security-research/security/advisories/GHSA-f5pg-7wfw-84q9	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:amazon:aws_s3_crypto_sdk:*:*:*:*:*:golang:*:*

History

No history.

Information

Published : 2020-08-11 20:15

Updated : 2023-12-10 13:27

NVD link : CVE-2020-8911

Mitre link : CVE-2020-8911

CVE.ORG link : CVE-2020-8911

JSON object : View

Products Affected

amazon

aws_s3_crypto_sdk

CWE

CWE-327

Use of a Broken or Risky Cryptographic Algorithm

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